Coin acceptors for testing the validity of inserted objects and coins have been in use for a long time. A common construction for a coin acceptor comprises a housing having a main plate and a track carrier plate parallel to and at a distance from the main plate. One or more track sections are located between the plates for allowing coins to pass therethrough. In electronic coin acceptors, sensors are placed in the plates for sensing different characteristics of passing coins. The track carrier plate is often hinged to the main plate. When a coin return knob is actuated in a vending machine, the carrier plate is pivoted away from the main plate so that any remaining coins can be removed or fall out. A spring pretensions or biases the track carrier plate to return the track carrier plate to its original position after it has been temporarily pivoted away by the actuation of the coin return knob.
A problem with existing coin acceptors is that, due to manufacturing tolerances and wear, the track carrier plate does not precisely move back to the original position in a reproducible fashion after pivoting out from the main plate. As a consequence, opposing sensors in the plates can be misaligned and variations in measured values or other measuring errors can occur. The constant loading of the track carrier by the pretensioning spring can also deform the track carrier, especially if it is made of plastic. This too can alter the alignment of the coin sensors. While the general concept of a film hinge is known, film hinges have not been used in conjunction with vending machines and coin acceptors.